The present invention is generally related to input devices for use with robots and the like, and particularly to robotic surgical devices, systems, and methods. In an exemplary embodiment, the invention provides a surgical robotic input device which can input both movement (for example, by moving the handle in both translation and orientation), and actuation (for example, by variably squeezing first and second grip members together), and which allows unlimited rotation of the handle about an axis of the handle.
Advances in minimally invasive surgical technology could dramatically increase the number of surgeries performed in a minimally invasive manner. Minimally invasive medical techniques are aimed at reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. The average length of a hospital stay for a standard surgery may also be shortened significantly using minimally invasive surgical techniques. Thus, an increased adoption of minimally invasive techniques could save millions of hospital days, and millions of dollars annually in hospital residency costs alone. Patient recovery times, patient discomfort, surgical side effects, and time away from work may also be reduced with minimally invasive surgery.
The most common form of minimally invasive surgery may be endoscopy. Probably the most common form of endoscopy is laparoscopy, which is minimally invasive inspection and surgery inside the abdominal cavity. In standard laparoscopic surgery, a patient""s abdomen is insufflated with gas, and cannula sleeves are passed through small (approximately xc2xd inch) incisions to provide entry ports for laparoscopic surgical instruments. The laparoscopic surgical instruments generally include a laparoscope (for viewing the surgical field) and working tools. The working tools are similar to those used in conventional (open) surgery, except that the working end or end effector of each tool is separated from its handle by an extension tube. As used herein, the term xe2x80x9cend effectorxe2x80x9d means the actual working part of the surgical instrument and can include clamps, graspers, scissors, staplers, and needle holders, for example. To perform surgical procedures, the surgeon passes these working tools or instruments through the cannula sleeves to an internal surgical site and manipulates them from outside the abdomen. The surgeon monitors the procedure by means of a monitor that displays an image of the surgical site taken from the laparoscope. Similar endoscopic techniques are employed in, e.g., arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy, cisternoscopy, sinoscopy, hysteroscopy, urethroscopy and the like.
There are many disadvantages relating to current minimally invasive surgical (MIS) technology. For example, existing MIS instruments deny the surgeon the flexibility of tool placement found in open surgery. Most current laparoscopic tools have rigid shafts, so that it can be difficult to approach the worksite through the small incision. Additionally, the length and construction of many endoscopic instruments reduces the surgeon""s ability to feel forces exerted by tissues and organs on the end effector of the associated tool. The lack of dexterity and sensitivity of endoscopic tools is a major impediment to the expansion of minimally invasive surgery.
Minimally invasive telesurgical robotic systems are being developed to increase a surgeon""s dexterity when working within an internal surgical site, as well as to allow a surgeon to operate on a patient from a remote location. In a telesurgery system, the surgeon is often provided with an image of the surgical site at a computer workstation. While viewing a three-dimensional image of the surgical site on a suitable viewer or display, the surgeon performs the surgical procedures on the patient by manipulating master input or control devices of the workstation. The master controls the motion of a servomechanically operated surgical instrument. During the surgical procedure, the telesurgical system can provide mechanical actuation and control of a variety of surgical instruments or tools having end effectors such as, e.g., tissue graspers, needle drivers, or the like, that perform various functions for the surgeon, e.g., holding or driving a needle, grasping a blood vessel, or dissecting tissue, or the like, in response to manipulation of the master control devices.
While the proposed robotic surgery systems offer significant potential to increase the number of procedures that can be performed in a minimally invasive manner, still further improvements are desirable. In particular, known robotic input or master control devices do not generally provide a surgeon with the freedom of movement that may be available in open surgery. While existing input devices such as three-dimensional joysticks, exoskeletal gloves, and the like, provide significant freedom of movement in both orientation and translation within a virtual workspace, the structures often impose limits on the total amount of rotation. More specifically, surgeons in both open and minimally invasive surgical procedures are free to release a handle of a surgical device in one orientation and grasp it an alternative orientation. This releasing and re-grasping may occur several times during a procedure, so that the surgical instrument is, in total, rotated several times about its axis. Work in connection with the present invention has indicated that the limited rotation capabilities of known robotic surgical input devices can be a source of delay of the surgical procedure.
Still further refinements in input devices for robotic surgery would be desirable. For example, it is generally desirable to avoid inadvertent movement of a surgical end effector. Additionally, it is generally desirable to provide differing input devices for use with different surgical end effectors, or for use by differing surgeons or other system operators.
In light of the above, it would generally be desirable to provide improved input devices for directing movement of robots, and particularly for use in robotic surgery.
The present invention generally provides improved input devices, systems using such input devices, and related methods. In particular, the invention provides robotic systems having input devices that are particularly well suited for use in robotic surgery. The surgical input devices will often include a handle which can be both moved and actuated by a hand of a system operator. The hand will often actuate the handle by variably squeezing a pair of grip members together so as to articulate jaws of a surgical end effector, such as forceps, scissors, clamps, needle holders, and the like. Rather than sensing actuation of the handle with a sensor mounted on the handle itself, a signal may be transmitted from the handle to a sensor mounted on a linkage supporting the handle via one or more joints. The signal will preferably be sent using a mechanical actuation indicator which moves in response to the actuation input, the actuation indicator often comprising a compression rod which is arranged co-axially with an axis of rotation of the joint coupling the member to the handle. Advantageously, this arrangement can allow the sensor to detect actuation independent of movement about the joint, and also allows unlimited rotation of the handle. This arrangement also facilitates removal and replacement of the actuable handle, allowing alternative handles having differing characteristics to be mounted for different surgical end effectors, different system operators, different surgical procedures, or the like.
The invention also provides input devices which include sensors to verify that a hand of a system operator is in contact with the handle. Such a sensor can avoid inadvertent movement of the handle and surgical end effector, for example, when the linkage supporting the handle is accidentally bumped as the system operator is reaching for the handle.
In a first aspect, the invention provides a surgical robotic input device comprising a handle actuatable by a hand of an operator so as to define a variable actuation input. The handle is also moveable by the hand of the operator to define a movement input. A structural member supports the handle so that the handle is rotatable about an axis relative to the member. An actuation indicator extends from the handle toward the member. The indicator moves relative to the member in response to the actuation input. An input sensor is supported by the member. The input sensor generates a signal in response to movement of the indicator relative to the member. The input signal is independent of rotation of the handle about the axis.
Typically, the handle will pivotally engage the member at a joint which defines an axis. At least a portion of the indicator will often move co-axially with the axis when the handle is actuated. The handle and indicator will often be detachably coupled to the member and sensor, respectively, easing removal and replacement of the handle, particularly where the indicator comprises a compression rod. In the exemplary embodiment, the member is supported by a linkage providing six degrees of freedom, thereby allowing movement of the handle in both position and orientation. The actuation input will often comprise variably squeezing first and second grip members together.
In another aspect, the invention provides a surgical robotic apparatus for performing a surgical procedure on a patient body. The surgical apparatus robotically moves a surgical end effector so as to effect the surgical procedure in response to movement of an input handle by a hand of a system operator. The surgical robotic apparatus comprises a touch sensor system coupled to the handle. The touch system generates a first signal in response to coupling of the handle with the hand of the operator. The surgical robotic apparatus is enabled to an operative state in response to the first signal.
Typically, the surgical robotic apparatus will be reconfigured to an alternate state when the touch system generates a second signal. The touch system will generate this second signal in response to decoupling of the hand of the operator from the handle. The surgical robotic apparatus in the alternate state will inhibit movement of the end effector.
Optionally, the touch system may induce a vibration in the handle so as to sense coupling of the hand of the operator and the handle by measuring the induced vibration. In some embodiments, a piezoelectric element may be used to induce and/or sense the vibration. In other embodiments, one or more joint motors may be provided to drive a joint of a linkage supporting the handle, often to provide some force feedback to the operator of forces being imposed on the surgical end effector, for repositioning of the handles, or the like. The touch system may optionally induce a vibration in the handle by oscillating the joint motor, and can sense the induced oscillation using a joint actuation sensor. Such joint actuation sensors are often present for sensing handle movement inputs. The touch sensor system may be used in addition to other safety devices such as a view sensor system which can verify that the operator is viewing a display of the surgical site, typically by sensing whether the operator""s head is disposed adjacent a binocular eye piece of a stereoscopic display system.
In another aspect, the invention provides a method for controlling a robotic system. The method comprises inputting commands to the robotic system by moving a handle of the robotic system with a hand of a system operator so as to articulate a pivotal joint. Commands are also input by actuating the handle with the hand. Movement of the handle is sensed by measuring articulation of the joint. Actuation of the handle is sensed by mechanically transmitting an actuation signal across the joint to an actuation sensor, and by measuring the mechanically transmitted actuation signal with the actuation sensor. An end effector is moved in response to the measured articulation of the joint, and in response to the measured actuation sensor.
Preferably, the mechanical transmitting step will comprise moving a compression rod co-axially with an axis of the joint. This facilitates movement of the handle about a handle support structure using a joint that can accommodate unlimited rotation of the handle. Such remote sensing of handle actuation also facilitates removal and replacement of the handle, often by handles having one or more differing characteristics.
In yet another aspect, the invention provides a robotic method comprising enabling an robotic apparatus to an operative state in response to coupling of a handle of the robotic apparatus with a hand of a system operator. Commands are input to the robotic apparatus by moving the handle with the hand of the operator. An end effector is moved in response to the input commands. The robotic apparatus is reconfigured to an alternate state in response to decoupling of the hand of the operator from the handle so as to inhibit inadvertent movement of the end effector. This is particularly advantageous when the handle moves in a plurality of degrees of freedom, as inadvertent bumping of the linkage supporting the handle will not lead to unintended movement of the end effector.
In one aspect of the invention, a master control input device is provided which is particularly advantageous for employment in master-slave robotic systems which benefit from orientational and/or positional alignment of a master device with respect to a corresponding associated slave device, and most particularly in robotic surgical systems which include an endoscope viewer or display. The master input device may be re-oriented in a roll degree of freedom without angular limit, thus permitting re-alignment following a large change in orientation of the slave with respect to the master, such as when a particular master device is switched from controlling a first robotic arm to controlling a second robotic arm. This aspect of the invention is also usefully employed in other systems involving alternative or complex associations of master and slave devices.
The International Application published as WO 00/60421 (incorporated by reference herein) describes, among other things, methods and devices for establishing a desired alignment or orientational relationship between a hand-held part of a master control and an end effector of an associated slave of a telerobotic system as viewed in an image displayed on a viewer. In an example comprising a typical robotic minimally invasive surgical system, the methods described therein provide for aligning an end effector of a slave surgical instrument, as shown in an endoscope image display or viewer, with a corresponding master handle operable by a surgeon.
One preferred method described in WO 00 60421 includes: causing the end effector to remain stationary; determining a current orientation of the end effector relative to a viewing end of an endoscope associated with the viewer; determining a desired corresponding orientation of the master handle relative to the viewer; and causing the master handle to be moved into the desired corresponding orientation. For example, this method permits the master and slave to be so aligned that the slave end effector appears to the operator in the viewer to be an extension of the master handle, a particularly intuitive or natural arrangement.
The methods described in WO 00 60421 extend to a control system arranged to cause the desired orientational relationship between the master handle and the end effector as viewed in the viewer, to be established and/or to be re-established or remapped when operative control between the master control and the slave has been interrupted. Examples include the removal of a surgical instrument from a robotic slave arm and the substitution of a new instrument, or another event which changes or disturbs the alignment, orientational and/or positional mapping of master to slave. Typically, the master handle will have more than one degree of freedom (DOF), one of which may be a handle roll DOF about a handle roll axis, which in turn operatively controls movement of an associated slave instrument about an instrument roll axis. Preferably, a desired orientational mapping of the roll DOF between master and slave is established or re-established by the methods described.
The International Application published as WO 00/30548 (also incorporated by reference herein) describes, among other things, methods and devices for selectably associating control effect for master/slave pairs in a robotic system. In an example comprising a typical robotic minimally invasive surgical system, the methods described therein provide for a surgeon using a particular master control handle to control more than one slave arm, e.g., by selectably switching the operative control effect of the master handle between a first slave arm and a second slave arm.
In one preferred surgical system embodiment described in WO 00 30548, a surgeon, in a cooperative operative procedure, may control an endoscope arm (by one of a number of alternative control means), may control a pair of left and right surgical instrument slave arms (using e.g., corresponding right and left hand master handles), and may also control at least one additional slave arm (e.g., using either the right or the left hand master handle) for at least one additional function, such as for stabilizing, retracting, or other functions benefiting from intermittent movement.
Following a large change in orientation of the slave with respect to the master, such as when a particular master device is switched or clutched from controlling a first robotic arm to controlling a second robotic arm, it may be desired to re-orient a master control device (e.g., a surgical system master handle) through a large roll angle, e.g., a roll angle of more than +/xe2x88x9290xc2x0.
In a case where control effect of the master is being switched from one slave instrument to another slave, a quick transition is beneficial to avoid interrupting the flow of the surgical procedure. If the range of roll motion of the master device is limited, a realignment of the master roll axis by more than +/xe2x88x9290xc2x0 typically may require that the surgeon to let go of the master handle in order to re-grasp it at a more convenient angle. This can be slow and cumbersome, and may significantly interfere with the flow of the operation.
In addition, if the range of roll motion of the master device is limited, even if each individual master realignment upon transition or switching between slave instruments is comparatively small, the cumulative roll motion of the master device after several such transitions may reach the master roll limit, and frustrate further realignments (e.g., if the surgeon performs most of the sequential adjustments in the same direction).
Thus, by providing a master device with is not limited in roll motion, the invention allows master device roll realignments to occur without re-grasping the master and without interruption to the flow of the surgical procedure. Employing a preferred embodiment of the invention, such an roll axis adjustment to the master device optimally matches the slave roll range of motion to that of the master, so that the surgeon""s motion is not restricted by the master joint roll limits. Thus the surgeon""s control is only restricted by such roll limits as may be inherent in the particular associated slave instrument. In the event that the slave also is unrestricted in roll motion, the preferred master control device embodiments of the invention permit such a slave device to be used to optimal effect.